1. Field
The present invention relates to a time management apparatus and a time management method.
2. Description of the Related Art
In recent years, with the prevalence of communication networks such as the Internet, users can acquire content information via networks. For example, in the case where content information is delivered via a network, information for managing a playback period of content information is, in some cases, added to the content information, thereby limiting the period during which viewing/listening is allowable.
There has conventionally been proposed a playback time management system wherein in the case of playing back information of recording module in which playback permission time data is recorded, an information playback permission time is determined after a standard time is acquired and the clock in a playback apparatus is corrected on the basis of the acquired standard time.
For example, as methods of managing the clock which is mounted in a content information playback apparatus, there are known a method (Mode A) without an anti-tampering function, and a method (Mode B) with an anti-tampering function which prevents an arbitrary change of time by a user.
In the case of recording time-managed content information in recording module such as a recording medium and playing back the time-managed content information by a plurality of playback apparatuses, the time information is managed by a plurality of clocks. Thus, there are cases in which a user who purchased the content information cannot play it back.
For example, in the case where the clock in the playback apparatus, which manages the clock by the Mode A method, is set at a future time relative to the present time, if content is played back by this playback apparatus, future time information is recorded as time management information in the recording module.
If the recording module in which such future time information is recorded is connected, for example, to an apparatus having a clock which is managed by the Mode B method, there occurs such a case that a content viewing/listening allowable period fails to be determined and content cannot viewed/listened to.